The present invention relates to chemical compositions useful for treating seeds. In particular, the present invention relates to a chemical composition useful for treating seeds to allow for planting and growing of seedlings under stressed conditions.
Yield of various crops is affected by the conditions to which seeds and seedlings of such crops are exposed. Seeds are the part of a plant that typically contain an embryo, stored food, and a protective coat thereon. Young plants grown from seeds are generally referred to as seedlings. Such relatively small, immature forms are more susceptible to harsh environments and diseases than their mature counterparts.
Seeds and seedlings may be exposed to one of, or a combination of, cold, drought, salt, heat, pollutants, and disease, conditions that potentially retard or prevent the growth of crops therefrom. For example, temperature extremes are typical in the upper Midwest region of the United States. Furthermore, diseases evolved from pathogens and deterioration caused by fungi are potentially harmful to seeds and seedlings. Thus, it is desirable to treat seeds with compositions that render the seeds and seedlings grown therefrom more hardy when exposed to such conditions.
Various agents have been used to treat seeds to increase resistance of the plants to stressed conditions, such as cold, drought, salt, and fungi. Such agents include, for example, sodium methylphenyl-pentadienate, O,N-diaryl-carbamate derivatives, choline, salts of choline, chlorocholine chloride, hydroxy-benzimidazole derivatives, trichloroacetic acid, polyoxyalkylene-organo-siloxane block copolymer, 5-aminolevulinic acid, carboxy-propionyl-amino-pyrrolidine, ethanolamine, 2-trimethylammonio-ethanol chloride, salicylic acid, potassium chloride, and polyvinyl alcohol. Many such agents have been used in aqueous solutions to impregnate and/or coat seeds. They can be used alone, or in combination, but typically only show positive effects on limited types of plants. Thus, there is a need for seed treatment compositions that can be used on a wider variety of plants to improve their resistance to a variety of stress conditions.
The present invention provides a chemical composition useful for treating seeds. The composition includes choline chloride, a calcium-containing salt, a potassium-containing salt, and salicylic acid. The choline chloride can be present at a concentration of about 5 millimolar to about 25 millimolar. The calcium-containing salt can be selected from the group of calcium nitrate, calcium chloride, and combinations thereof. The calcium-containing salt can be present in the composition at a concentration of about 20 millimolar to about 30 millimolar. The potassium-containing salt can be selected from the group of potassium chloride, potassium nitrate, and combinations thereof. The potassium-containing salt can be present in the composition at a concentration of about 20 millimolar to about 25 millimolar. The salicylic acid can be present in the composition at a concentration of about 50 micromolar to about 100 micromolar.
Optionally, the composition includes glycerol, which can be present at a concentration of, for instance, about 0.5% by volume to about 3.0% by volume. Optionally, the composition includes chlorocholine chloride, which can be present at a concentration of, for instance, about 5 micromolar to about 4 millimolar of chlorocholine chloride. Optionally, the composition can include an alkanolamine, which can be present at a concentration of, for instance, about 15 millimolar to about 25 millimolar.
In another aspect of the present invention, the chemical composition is essentially choline chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, and glycerol, or the chemical composition is essentially choline chloride, chlorocholine chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, an alkanolamine, and glycerol.
The present invention also provides a chemical composition useful for treating seeds that includes chlorocholine chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, and an alkanolamine, and does not include ((4-chlorophenyl)methyl)-(1,1-dimethylethyl)-1,2,4-triazole-1-ethanol. The alkanolamine can be present in the composition at a concentration of about 15 millimolar to about 25 millimolar. The chlorocholine chloride can be present in the composition at a concentration of about 5 micromolar to about 4 millimolar. The calcium-containing salt can be selected from the group of calcium nitrate, calcium chloride, and combinations thereof. The calcium-containing salt can be present in the composition at a concentration of about 20 millimolar to about 30 millimolar. The potassium-containing salt can be selected from the group of potassium chloride, potassium nitrate, and combinations thereof. The potassium-containing salt can be present in the composition at a concentration of about 20 millimolar to about 25 millimolar. The salicylic acid can be present in the composition at a concentration of about 50 micromolar to about 100 micromolar. Optionally, the composition includes glycerol, which can be present at a concentration of, for instance, about 0.5% by volume to about 3.0% by volume.
Another aspect of the present invention provides a method for treating seeds with a composition of the present invention. The seed can be, for instance, a corn seed or a soybean seed. The method can also include planting the seed.
The present invention provides seed treatment compositions useful for treating seeds of a variety of plants, including, for example, corn and soybean. A seed treatment composition according to the present invention can show desirable effects on plants when exposed to drought, cold, heat, and salt, for example.
For example, a seed treatment composition of the present invention can potentially enhance (i.e., increase) at least one of the following: seed emergence rate from soil, early vigor of seedlings; growth and development of seedlings; and crop yield. Significant improvements in root growth and development (e.g., one or more of branching, length of roots, diameter of roots, number of lateral roots, root nodules) have been observed in seedlings grown from seeds treated with a seed treatment composition of the present invention. Likewise, significant improvements in crop growth (e.g., one or more of increased height of the crop, increased plant fresh weight, minimized leaf chilling damage, minimized leaf drought damage) have been observed in crops grown from seeds treated with a seed treatment composition of the present invention. Although not intending to be limiting, it is believed that these positive effects result from stabilizing the cell membranes, in order to maintain cell properties as would exist under moderate environmental conditions.
The seed treatment compositions of the present invention include a combination of several components, typically at least four, preferably at least five, more preferably at least six, and most preferably at least seven components. It has been discovered that a mixture of the components described herein is effective on a wider variety of plants than are the individual components. Also, it has been discovered that a mixture of components described herein is typically more effective than are the individual components therein.
In some aspects of the invention, the compositions include choline chloride, a calcium-containing salt, a potassium-containing salt, and salicylic acid. Optionally, the compositions further include glycerol, chlorocholine chloride, or an alkanolamine. Alternatively, the compositions are essentially choline chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, and glycerol. In another aspect of the invention, the compositions include chlorocholine chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, and an alkanolamine, and do not include ((4-chlorophenyl)methyl)-(1,1-dimethylethyl)-1,2,4-triazole-1-ethanol. Optionally, the compositions further include glycerol. Alternatively, the compositions are essentially choline chloride, chlorocholine chloride, a calcium-containing salt, a potassium-containing salt, salicylic acid, an alkanolamine, and glycerol. Typically, the compositions of the present invention are used in combination with a diluent, such as water, to prepare an aqueous mixture.
Choline ((CH3)3N(OH)CH2CH2OH) is found in many plant species. It is a precursor of, for example, acetylcholine and lecithin. The inclusion of at least one choline-containing compound in the compositions of the present invention is thought to improve the effectiveness of enzymes present in cell membranes of plants. The choline-containing compound is typically used in the compositions of the present invention in the form of a salt. Preferred choline-containing compounds of the present invention include choline chloride ((CH3)3N(Cl)CH2CH2OH), chlorocholine chloride ((ClCH2)3N(Cl)CH2CH2OH), and combinations thereof. Preferred compositions include both choline chloride and chlorocholine chloride. Depending on the species of crops, type of seeds, and type of choline-containing compound utilized, a composition of the present invention can include different amounts of the choline-containing compound. Preferably, a composition includes about 5 micromolar to about 25 millimolar of the choline-containing compound. In general, more choline chloride is needed than chlorocholine chloride for a particular type of seed. Examples of preferred lower concentrations of choline chloride are about 20 millimolar for corn seeds and about 5 millimolar for soybean seeds. Examples of preferred high concentrations of choline chloride are about 25 millimolar for corn seeds and about 10 millimolar for soybean seeds. Examples of preferred lower concentrations of chlorocholine chloride are about 2 millimolar for corn seeds and about 5 micromolar for soybean seeds. Examples of preferred high concentrations of chlorocholine chloride are about 4 millimolar for corn seed, and about 10 micromolar for soybean seeds. It has been found, however, that if the concentration of chlorocholine chloride is too high, the composition may not be as effective, and can harm the seeds such that the seeds do not germinate.
Calcium (Ca) is a mineral nutrient. Minerals are needed for proper growth and function of cells. The calcium is provided in the form of a salt that is at least partially soluble in water. It is believed that the inclusion of at least one calcium-containing salt in the composition of the present invention enhances the ability of cells to interpret and react to external forces, such as harsh environmental conditions or disease. Preferred salts for use in the compositions of the present invention include calcium nitrate (Ca(NO3)2), calcium chloride (CaCl2), and combinations thereof. Preferably, the calcium-containing salt is present in a composition of the present invention at a concentration of about 20 millimolar to about 30 millimolar.
Potassium (K) is also a mineral nutrient. The potassium is provided in the form of a salt that is at least partially soluble in water. The potassium salts are chosen such that they do not include a counterion that will precipitate the calcium out of solution. It is believed that the inclusion of at least one potassium-containing salt in the composition of the present invention enhances the ability of cells to react to external forces, such as harsh environmental conditions or disease. For example, potassium may play a role in controlling the osmotic potential in the cells of plants. Preferred salts according to the present invention include potassium chloride (KCl), potassium nitrate (KNO3), and combinations thereof. Preferably, the potassium-containing salt is present in a composition of the present invention at a concentration of about 20 millimolar to about 25 millimolar.
Salicylic acid (HOC6H4COOH) is commonly utilized in the manufacture of aspirin (acetylsalicylic acid) or as a food preservative. Salicylic acid is included in the composition to enhance cell resistance to pathogens and other stresses. Preferably, salicylic acid is present in a composition of the present invention at a concentration of about 50 micromolar to about 100 micromolar.
Optionally, and preferably, the compositions of the present invention include glycerol. Glycerol (C3H5(OH)3) is commonly utilized as a food preservative. It is believed that glycerol is useful in the compositions of the present invention as a transporter of the other components of the compositions across cell membranes. Glycerol is preferably present in a composition of the present invention at a concentration of about 0.5% by volume to about 3.0% by volume. More preferably, glycerol is present at a concentration of about 1% by volume.
Optionally, the compositions of the present invention include an alkanolamine. The alkanolamine can be a compound of the formula: HOxe2x80x94(CH2)nxe2x80x94NR1R2R3 or one of its acid addition salts, wherein n=2-5, and each of R1 and R2 are one of H or a C1-C5 alkyl, and R3 is one of H, a C1-C5 alkyl, or a free electron pair. A preferred alkanolamine is 2-aminoethanol. It is a product of the decomposition of fatty acids within the cell membranes of plants. Depending on the crop and structure of the seed, a composition can include different amounts of an alkanolamine. Preferably, when treating corn seeds, for example, an alkanolamine is present in a composition at a concentration of about 15 millimolar to about 25 millimolar. Preferably the alkanolamine is 2-aminoethanol.
When treating seeds according to the present invention, seeds are contacted with the composition. Contacting seeds with the composition includes coating seeds or soaking seeds. Preferably, the seeds are contacted with the composition by coating. Seeds can be soaked in an aqueous solution containing a chemical composition of the invention. For example, corn seeds can be soaked for about 12 to about 24 hours. Some types of seeds (e.g., soybean seeds) may be sensitive to moisture. Thus, soaking such seeds for an extended period of time may not be desirable. Seeds can be coated using a mixture of the chemical composition and melted gelatin (available from Electro Microscopy Sciences, Fort Washington, Pa.) or other commercially available materials such as that available under the trade designation MAGNA-COAT from Gustafson Co., McKinney, Tex, can be used to coat such seeds. Alternatively, a mixture of the chemical composition and a paste derived from sticky rice can be used to coat seeds. Preferably, seeds coated using such a paste are planted very soon after coating. Such compositions are typically sprayed on the seeds, although other techniques can be used such as dip coating. Another method to coat seeds involves coating the inside wall of a round container with the composition, adding seeds, then rotating the container to cause the seeds to contact the wall and the composition (referred to herein as container coatingxe2x80x9d). Seeds can be coated by combinations of coating methods. While not intended to be limiting, the composition is still effective at least 75 days after coating.
The chemical composition of the present invention is particularly useful in treating corn seeds and soybean seeds. The following examples are included for aid in understanding the beneficial uses of the chemical composition. Variations to the following examples are encouraged and well within the scope of the present invention.